The long-term objective of the proposed research is to provide an effective surface coating to reduce encrustation on urinary devices. Encrustation is one of the major complications associated with them, with an overall incidence of 10-58%, but a higher (64%) incidence in stone formers. To reduce this complication, we proposed to use a barrier coating to protect devices from pH elevation. Specific aim 1 is to establish an experimental model to create encrustation on testing subjects. The model is an in vitro, static incubation system with humidity and temperature control. With this model, specific aim 2 will test the hypothesis-constant surface pH reduces encrustation. Evaluation will be made based on the measurements of calcium deposition on testing subjects exposed to various pH conditions. Specific aim 3 concentrates on prolonging the effectiveness of anti-encrustation. The extension of effectiveness could be achieved by increasing the amount of active ingredients in the coating. The last specific aim is to evaluate the commercial potential of this new coating. Ureteral stents equipped with the anti-encrustation coating will be compared to many similar products on the market in the aspect of encrustation severity. The data will guide future optimization.